Spred the bread with some of the softened butter, make 4 sandwiches, each with one slice of ham and one of cheese. Press firmly together. Beat the eggs and water, salt and pepper and dip the sandwiches into the egg mixture, coating all sides well. Heat the rest of the butter in a heavy- bottomed skillet; when it is bubbly but not yet browned, fry the sandwiches, turning once. Serve immediatly, (if you prefer although it is not traditionnally done, you may place the croque-monsieur into a very well-buttered baking pan and bake in a moderately hot oven-- 350 d.F.-- turning once. It is easier to prepare a larger number this way and keep them warm till ready to serve.)